[DAG] Improve Aliasing of operations to static alloca

Memory accesses offset from frame indices may alias, e.g., we
may merge write from function arguments passed on the stack when they
are contiguous. As a result, when checking aliasing, we consider the
underlying frame index's offset from the stack pointer.

Static allocs are realized as stack objects in SelectionDAG, but its
offset is not set until post-DAG causing DAGCombiner's alias check to
consider access to static allocas to frequently alias. Modify isAlias
to consider access between static allocas and access from other frame
objects to be considered aliasing.

Many test changes are included here. Most are fixes for tests which
indirectly relied on our aliasing ability and needed to be modified to
preserve their original intent.

The remaining tests have minor improvements due to relaxed
ordering. The exception is CodeGen/X86/2011-10-19-widen_vselect.ll
which has a minor degradation dispite though the pre-legalized DAG is
improved.

Reviewers: rnk, mkuper, jonpa, hfinkel, uweigand

Reviewed By: rnk

Subscribers: sdardis, nemanjai, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33345

llvm-svn: 307546

1 files changed, 21 insertions, 21 deletions

diff --git a/llvm/test/CodeGen/X86/statepoint-stack-usage.ll b/llvm/test/CodeGen/X86/statepoint-stack-usage.ll
index b16426eae3d..6e7fc7bf1c0 100644
--- a/llvm/test/CodeGen/X86/statepoint-stack-usage.ll
+++ b/llvm/test/CodeGen/X86/statepoint-stack-usage.ll
@@ -11,9 +11,9 @@ target triple = "x86_64-pc-linux-gnu"
 define i32 @back_to_back_calls(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
 ; CHECK-LABEL: back_to_back_calls
 ; The exact stores don't matter, but there need to be three stack slots created
-; CHECK: movq	%rdi, 16(%rsp)
-; CHECK: movq	%rdx, 8(%rsp)
-; CHECK: movq	%rsi, (%rsp)
+; CHECK-DAG: movq	%rdi, 16(%rsp)
+; CHECK-DAG: movq	%rdx, 8(%rsp)
+; CHECK-DAG: movq	%rsi, (%rsp)
 ; There should be no more than three moves
 ; CHECK-NOT: movq
   %safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
@@ -36,9 +36,9 @@ define i32 @back_to_back_calls(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 a
 define i32 @reserve_first(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
 ; CHECK-LABEL: reserve_first
 ; The exact stores don't matter, but there need to be three stack slots created
-; CHECK: movq	%rdi, 16(%rsp)
-; CHECK: movq	%rdx, 8(%rsp)
-; CHECK: movq	%rsi, (%rsp)
+; CHECK-DAG: movq	%rdi, 16(%rsp)
+; CHECK-DAG: movq	%rdx, 8(%rsp)
+; CHECK-DAG: movq	%rsi, (%rsp)
   %safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
   %a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
   %b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
@@ -61,21 +61,21 @@ define i32 @back_to_back_deopt(i32 %a, i32 %b, i32 %c) #1
   gc "statepoint-example" {
 ; CHECK-LABEL: back_to_back_deopt
 ; The exact stores don't matter, but there need to be three stack slots created
-; CHECK: movl	%ebx, 12(%rsp)
-; CHECK: movl	%ebp, 8(%rsp)
-; CHECK: movl	%r14d, 4(%rsp)
+; CHECK-DAG: movl	%ebx, 12(%rsp)
+; CHECK-DAG: movl	%ebp, 8(%rsp)
+; CHECK-DAG: movl	%r14d, 4(%rsp)
 ; CHECK: callq
-; CHECK: movl	%ebx, 12(%rsp)
-; CHECK: movl	%ebp, 8(%rsp)
-; CHECK: movl	%r14d, 4(%rsp)
+; CHECK-DAG: movl	%ebx, 12(%rsp)
+; CHECK-DAG: movl	%ebp, 8(%rsp)
+; CHECK-DAG: movl	%r14d, 4(%rsp)
 ; CHECK: callq
-; CHECK: movl	%ebx, 12(%rsp)
-; CHECK: movl	%ebp, 8(%rsp)
-; CHECK: movl	%r14d, 4(%rsp)
+; CHECK-DAG: movl	%ebx, 12(%rsp)
+; CHECK-DAG: movl	%ebp, 8(%rsp)
+; CHECK-DAG: movl	%r14d, 4(%rsp)
 ; CHECK: callq
-; CHECK: movl	%ebx, 12(%rsp)
-; CHECK: movl	%ebp, 8(%rsp)
-; CHECK: movl	%r14d, 4(%rsp)
+; CHECK-DAG: movl	%ebx, 12(%rsp)
+; CHECK-DAG: movl	%ebp, 8(%rsp)
+; CHECK-DAG: movl	%r14d, 4(%rsp)
 ; CHECK: callq
   call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
 call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
@@ -89,9 +89,9 @@ define i32 @back_to_back_invokes(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32
 ; CHECK-LABEL: back_to_back_invokes
 entry:
   ; The exact stores don't matter, but there need to be three stack slots created
-  ; CHECK: movq	%rdi, 16(%rsp)
-  ; CHECK: movq	%rdx, 8(%rsp)
-  ; CHECK: movq	%rsi, (%rsp)
+  ; CHECK-DAG: movq	%rdi, 16(%rsp)
+  ; CHECK-DAG: movq	%rdx, 8(%rsp)
+  ; CHECK-DAG: movq	%rsi, (%rsp)
   ; CHECK: callq
   %safepoint_token = invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
                    to label %normal_return unwind label %exceptional_return